Warn about dropped message in filter #8579
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Buy default the `MessageFilter` just drops a discarded message silently. If a request-reply gateway is used upstream, then it becomes unclear why the flow sometimes doesn't work. * Add a waring log ot emit for default behavior. This still doesn't fix the request-reply problem, but at least it can give a clue what is going on
| } | ||
| if (this.throwExceptionOnRejection) { | ||
| throw new MessageRejectedException(message, "message has been rejected in filter: " + this); | ||
| } | ||
| else if (channelToDiscard == null) { | ||
| logger.warn(LogMessage.format("The message [%s] has been rejected in filter: %s", message, this)); |
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WARN seems too strong; this might be the desired behavior; I would suggest DEBUG, perhaps with an option to increase the log level.
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OK. As a middle group I can agree for an INFO, which seems a default one for Spring Boot.
Sure! It can be desired behavior when you know what you do.
But if your expectation is request-reply and you miss the fact that simple filter() in the middle of the flow just drops messages silently, it would be great if framework notifies you some way what is going on instead of silence.
Another way I'd suggest is to configure a nullChannel as a discardChannel if you'd like to ignore everything silently.
I also can go more aggressive path and make a throwExceptionOnRejection as default behavior.
So, when we develop everything in default, there is no any silence.
FYI: the next my change will be to fix gateway for its infinite default reply timeout (After you merge that doc PR).
The recommendation in modern design is to never block forever.
This is going to be another signal in the mentioned request-reply and filter scenario that something is not OK or misconfigured 😄 .
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I have no objection to requiring nullChannel, if it's only a 6.1 change.
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Yes, it is. Let me add such a sentence into doc and you are feel free to merge thereafter!
Co-authored-by: Gary Russell <[email protected]>
Buy default the
MessageFilterjust drops a discarded message silently. If a request-reply gateway is used upstream, then it becomes unclear why the flow sometimes doesn't work.